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Q138398: PRB: RELEASE May Not Remove OLE Objects from Memory

Article: Q138398
Product(s): Microsoft FoxPro
Version(s): WINDOWS:3.0,5.0,5.0a,6.0
Operating System(s): 
Keyword(s): 
Last Modified: 28-MAY-1999

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The information in this article applies to:

- Microsoft Visual FoxPro for Windows, versions 3.0, 5.0, 5.0a, 6.0 
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SYMPTOMS
========

After creating an OLE object using the CREATEOBEJCT() function, releasing that
object does not remove the OLE application session from memory.

RESOLUTION
==========

For Visual FoxPro to remove certain OLE application session objects from memory,
the OLE application must be terminated. For example, after running the following
code, three instances of Microsoft Excel remain in memory:

     FOR i = 1 TO 3

         oObject = CREATEOBJECT('Excel.Application')
         RELEASE oObject

     ENDFOR

To end each Microsoft Excel session before reentering the FOR loop, the Microsoft
Excel session must first be terminated. For example:

     FOR i = 1 TO 3

         oObject = CREATEOBJECT('Excel.Application')
         oObject.Quit
         RELEASE oObject

     ENDFOR

In this example, Microsoft Excel is told to quit, and then the code releases the
memory variable in Visual FoxPro by using the oObject.Release command. Quit is a
method that Microsoft Excel recognizes and can act upon, the actual method for
your OLE automation application may differ.

STATUS
======

This behavior is by design.

MORE INFORMATION
================

The OLE Automation release method is program specific. In the previous example,
Microsoft Excel was used. Microsoft Excel version 7.0 is designed to remain in
memory after a OLE object is released. However, other programs may behave
differently. For example, Microsoft Word version 7.0 terminates with just a
RELEASE command.

For more information on how your program will handle an OLE Automation RELEASE
command, please refer to that program's documentation or refer to the vendor of
that program.

Steps to Reproduce Behavior
---------------------------

1. Run this code:

     FOR i = 1 TO 3
        
         oObject = CREATEOBJECT('Excel.Application')
         WAIT WINDOW 'Created Excel Object' + STR(i)
         RELEASE oObject

     ENDFOR

2. View the Windows Task List, and notice that three sessions of Microsoft Excel
  remain in memory.

Additional query words: VfoxWin kbvfp300 kbvfp500 kbvfp500a kbvfp600

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Keywords          :  
Technology        : kbVFPsearch kbAudDeveloper kbVFP300 kbVFP500 kbVFP600 kbVFP500a
Version           : WINDOWS:3.0,5.0,5.0a,6.0
Issue type        : kbprb

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